MagicQ70 firmware upgrade for early consoles

The first batch of MQ70s shipped in 2019 have the following deficiencies:

* Cannot playback MP3 files
* Cannot playback multiple audio files at the same time
* Show folder not accessible over the network as a Windows share (SMB)

As these are part of the core operating system, they cannot be fixed by
updating MagicQ. Instead, a special CDZ upgrade file has been created
which will fix these issues - this update file only needs to be
installed once.

All new consoles shipped from now on do not need this upgrade as they
run a newer operating system.

Generally, this will affect consoles with serial numbers CH8070248190085
and older. These have 'pre v7' operating system.

You can check the operating system version in SETUP -> VIEW SYSTEM ->
VIEW STATUS -> System -> OS version. If this shows v6 or lower, then it
will need this update. Once this update has been installed, it will
still show the same OS version number, but will be appended with
"[pulseaudio mp3-flame]".

Users should upgrade their console to at least 1.8.4.9 (or the stable
version 1.8.5.0 when it is released) first.

The CDZ file can be downloaded at the following URL, and installed on
the console in the same way as a regular MagicQ update: